Two-stroke internal-combustion engine



Maw Ti hfl.[A3KJlS TWO-STROXEI INTERNAL COMBUSTION ENGINE Filed Nov. 2, 1926 2,Sheets Sheet 1 May 14, 1929. M. LOUIS 1,112,963 A TWO-STROKE INTERNAL COMBUSTION ENGINE Filed Nov. 2, 1926 2 Sheet-Sheet 2 Fig.4 Fig.6.

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Patented May 14, 1929.

UNITED STATES PATENT OFFICE.

MARTIN LOUIS, OF KIEL, GERMANY, ASSIGNOR 10 FRIED. KRUPB GERMANIAWERFT .AKTIENGESELLSCHAFT, OF KIEL GAARDEN, GERMANY.

TWO-STROKE INTEBNAL-COMBUSTION ENGINE.

Application fi1ed November 2, 1926, Serial No. 145,855, and in Germany November 17, 1925.

The invention relates totwo-stroke internal combustion engines the inlet and outlet ports of which are controlled by-the working piston, and has more particularly for its object to improve the direction of flow of the scavenging medium in the cylinder so that the scavenging is more complete and ellicient than heretofore.

This object is attained according to the invention by the outlet ports being arranged in the rear portion of the cylinder wall and by the groups of inlet ports being displaced towards the front portion of the cylinder and so directed that all the branch scavenging currents entering through them unite into a single closely confined current at the rear portion of the cylinder wall above the outlet ports. be united current ascends on the rear portion of the cylinder wall, flows along the cover, descends on the front portion of the cylinder Wall and llows, below the entering branch currents along the piston surface, to the outlet ports.

In the accompanying drawing:

inder constructed in accordance with my invention Fig. 2 is a horizontal section thereof,

Fig. 3 is a diagrammatic view showing the course of the scavenging air within the cylinder,

Fig. 4; is a vertical medial section of a double acting engine cylinder constructed in accordance with my invention,

Fig. 5 is a horizontal section thereof, and

Fig. 6 is a vertical section on the line 6-6 of Fig. 5.

A denotes the cylinder of a two-stroke Diesel engine, the scavenging ports B and outlet ports G of which are controlled by the piston D. The inlet ports B are arranged on the side portions of the cylinder so as to form two opposite groups, and have an upwardly inclined direction towards the rear portion of the cylinder wall. The outlet ports C are arranged in the middle of the rear portion of the cylinder Wall between the groups of inlet ports and in substantially the same transverse plane of the cylinder. The entire scavenging air takes the course to be seen from the figures, especially from Fig. 3.

With the described arrangement of the inlet and outlet ports the scavenging current passes through the cylinder room in a c0ntinuous course without any forced defiec- Fig. 1 is a vertical medial section of a cyltion, and in the same sense of rotation from the beginning to the end. The above described closely conlined current causes a com-- plete scavenging even of the upper corners of the cylinder, without a portion of the scavenging air escaping directly through the outlet ports and thus not partaking of the scavenging action, as easily happens in known cross scavenging methods. The arrangement further results in the advantage that the scavenging air descending along the front portion of the cylinder wall follows the natural and forced deflection by the piston, that is, inward across the piston face, in particular with a piston having a recessed front face, and not being deflected, as in known scavenging arrangements against this natural deflection outward into the outlet ports. This natural deflection by solid boundary faces thus takes place in the described engine not only at the place just mentioned, but wherever the current of the scavenging air is subjected Within the cylinder to a deflection from its direction. Consequently at none of these places is a back pres sure against the gaseous content of the cylinder caused by the scavenging current which is being deflected, and thus there is no increase of the pressure in the cylinder, so that it is possible to decrease to a minimum the pressure of the scavenging air. Besides with the scavenging according to the invention the angular section located below the entering branch currents and not reached by the ascending current is completely scavenged by the escaping scavenging current on its way along the piston face. To improve the course of the scavenging air the tall inlet ports B may be subdivided by conduit plates of known construction.

The displacement of the inlet ports towards the front portion of the cylinder Wall finally enables all the inlet ports, even those located close to the outlet ports, to be so directed that the jets of scavenging air entering through them aim towards the rear portion of the cylinder wall, this causing a closely confined ascending column of the scavenging air along this rear wall portion.

A particularly advantageous arrangement of this kind is one in which the inlet ports are directed so as to cause the scavenging air currents entering through them to flow tangcntially to a virtual cylinder coaxial with the working cylinder. \Vith double acting engines, this virtual cylinder might coincide on the piston rod side about with the shell surface of the piston rod.

In the double acting engine shown in Figs. 4 to G the arrangement of the inlet ports B and outlet ports C is the same as in the liist described single acting engine and. to save. structural height, the arrangement is in a Well known manner so chosen, that the said ports are common to both cylinder halves.

As the arrows indicate, the scavenging air currents entering through the inlet ports I) arrive behind the piston-rod in a direction substantially tangential to the latter. They unite as in the first-described embodiment above the outlet ports between the piston rod and cylinder wall into a closely confined current which ascends on the. rear portion of the cylinder wall, flows along the cover around the piston-rod (Z descends between pistonrod and front portion of the cylinder Wall and flows to the outlet ports around the piston-rod again and across to and below the entering scavenging air currents.

As the passage-area for the scavenging air striking over the piston face is considerably narrowed on the piston-rod side of such a rod side.

. as the air is forcedly conducted around the piston-rod by the cavitv. which is adapted to the shape of the cylinder. A similar conduct might easily be attained also on the stutling box side of the lower half ot the cylinder by correspondingly shaping the cover or by insorting a deeply recessed ater chamber. Such a water chamber is indicated in Fig. t in dotted lines.

As the inlet ports are to serve to conduct the scavenging air of the upper and lower cylinder half, as already mentioned. the conduit plates, provided to this end. are adapted to be thrown over. To this end they are linked to the cylinder with their inner extremities. whilst the outer ends are capable of being so moved up and down by means ot a common drive, that they are directed upward, when the piston assumes its lowern'iest position. but downward, when it t: lUS its uppermost. position. The actuation of the conduit plates oi all the scavenging ports may he eli'ected from a single shaft. which is actuated from 1 der, a piston adapted to reciprocate therein is not limited, it may be suitable to give up the ports common to the upper and lower cylinder half and to arran; e the ports l'o both sides of the cylinder according to the [ii-stale scribed embodiment. in this case it is not rcouircd to provide conduii plates adapted to be thrown over.

Claims:

1. In a lwo strolv'e cycle internal combos-- tion engine. a cylinder, a piston adapted to reciprocate therein. and inlet and outlet ports for a scavenging medium in the wall ol' aid cylinder controlled by said piston. said inlet ports being arranged in two groups on opposite sides of the cylinder, the ports ol' each group being dircctcd toward a portion ol lhc cylinder wall between said inl t ports and nearer to the cylinder cover than said inlet ports. said outlet ports bciug located in sub stantially the same transverse plane ol the cylinderwithsaid iulct ports on the side l' l he cylinder toward which said inlct ports are directed.

2. In a two-strobe cycle internal co)lllilI.--'- tionenginc. a cylinder. a plrdoll adapted to rcciprocate therein. and inlet and outlet ports for a. scavenging medium in the wall ol said cylinder controlled by said piston. said inlet ports being arranged in two groups on opposite sides of the cylinder. the ports of each group being directed along lines tangent to a common virtual cylinder coaxial with the working cylinder, and directed also toward a portion o'lthe cylinder wall nearer to the cylinder cover than said inlet ports, said out-- let ports being located in substantially the same transverse plane of the cylinder with said inlet ports in the side of the cylinder to ward which said inlet ports are directed.

In a double-acting tWo-strohc cycle in-- ternal combustion engine comprising a. cylinand a piston rod connected to said piston. the, combination with the piston rod cud ol said cylinder of inlet and outlet ports for a scavcnging medium in the wall of said cylinder,

said inlet ports being arranged in two groups on opposite sides of the cylinder. the ports of each group being directed toward a portion of the cylinder wall hetwccn said inlet ports and nearer to the cylinder cover than said in-- let ports, said outlet ports being located in subs-taut ial ly the same transvcrsc plane of the cylinder with said inlet ports on the side f the cylinder toward wl ich said inlet port are directed. and a spherical recess in the piston rod end of said piston having a volume equal to the space occupied by said piston-rod.

t. in a double-acting twoslrolto cycle in lcrual combustion engine comprising a cylin d r. :1 pi ton adapted to recipiocate therein. and a piston rod connected to said piston. the combination with the piston rod end of said. cylinder of; inlet and outlet. ports for a s av enging medium in the wall of said. cylinder.

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llltl said inlet ports being arranged in two groups on opposite sides oi the cylinder, the ports of each group being directed toward a portion of the cylinder wall between said inlet ports and nearer to the cylinder cover than said inlet ports, said outlet ports being located in substantially the same transverse plane of the cylinder with said inlet ports on the side of t-hccylindcr toward which said inlet ports are inclined. a spherical recess in the piston-rod end of said piston having a volume equal to the space occupied by said piston-rod, and a spherical recess in the cylinder cover.

5. In a double-acting two-stroke cycle internal combustion engine comprising a cylinder, a piston adapted to reciprocate therein, and a piston rod connected to said piston, the combination with the piston rod end of said cylinder of inlet and outlet ports for a seavenging medium in the wall of said cylinder, said inlet ports being arranged in two groups on opposite sides of the cylinder, the ports of each group being directed along lines tangent to the piston rod, and 'rected also toward a portion of the cylinder wall nearer to the cylinder cover than said inlet ports, said outlet ports being); located in substantially the same transverse plane of the cylinder with said inlet ports in the side of the cylinder toward which said inlet ports are inclined.

6. In a douhle-acting two-stroke cycle internal combustionengine, a cylinder, a piston adapted to reciprocate tl'i'erein, inlet and outlet ports for a scavenging medium common to both ends of said cylinder and controlled by said piston, said inlet ports being arranged in two groups on opposite sides of the cylinder, conduit plates pivotally mounted before said inlet ports, and means for turning said conduit plates on their pivots in time with the stroke of the piston, said conduit plates, when in one limit position, being adapted to directthe scavenging medium toward a portion of the cylinder wall between said groups of inlet ports and nearer to one cylinder cover than said inlet ports, and when in the other limit position being adapted to direct the scavenging medium toward a portion of the cylinder wall between said groups of inlet ports and nearer to the other cylinder cover than said inlet ports, said outlet ports being arranged in that side of the cylinder wall toward which said inlet portsare directed and substantially in the same transverse plane with said inlet ports.

The fore' oin s )ecificat-ion si ned at Hamb 1:

burg, Germany, this 11th day of October, 1926.

MARTIN LOUIS. 

